Umbilical veins
Definition :
One of three embryonic vessels of
fetus .
Veins of fetus
•
Vitelline
system : develops portal system
•
Umbilical
system : which disappear after birth
•
Cardinal
system : forms caval system
Fetal circulation :
it enters the embryo body at the
umbilicus and
then passes into the liver, where it is joined
by the portal vein;
its blood then
flows by way of the
ductus venosus and
the inferior vena
cava to the right
atrium
Fate of
umbilical veins :
the right umbilical vein disappears
during the seventh
week.
it
is degenate at least a week after birth
Fucntions:
It functions to return the blood from
the placenta and fuses to form a single vein in the umbilical cord.
Applied anatomy :
Recanalization :
Under extreme pressure,
the round ligament may reopen to allow the passage of blood. Such
recanalization may be evident in patients with cirrhosis and portal
hypertension.
Catheterization :
A newborn baby has a patent umbilical vein for at least a
week after birth. This umbilical vein may be catheterised for ready intravenous
access.
